1956 Grand Canyon mid-air collision, 1986 Cerritos mid-air collision, Avianca Flight 52, Gol Transportes Aéreos Flight 1907, Überlingen mid-air collision.<br /> <br /> This special looked at the role of air traffic controllers in the airline industry, and took a look at the Next Generation Air Transportation System, a new technology meant to eliminate mid-air collisions by reducing overall dependence on radar and radio, as well as delegating some of the air traffic controllers' tasks to computers on board each plane.

Southern Airways Flight 242, Delta Air Lines Flight 191, American Airlines Flight 1420, British Airways Flight 9.<br /> <br /> This special looked at the role of bad weather in disasters and examines the US Aviation Weather Center in Kansas City, Missouri, to see how information on weather is transmitted to pilots in the sky.